Morbidly Adherent Placenta: Interprofessional Management Strategies for the Intrapartum Period

Feasibility Study of Ferumoxtyol for Contrast-enhanced MRI of Retroplacental Clear Space Disruption in Placenta Accreta Spectrum (PAS)

INTRODUCTION

Placenta accreta spectrum (PAS) occurs when the placenta is pathologically adherent to the myometrium. An intact retroplacental clear space (RPCS) is a marker of normal placentation, but visualization with conventional imaging techniques is a challenge. In this study, we investigate use of an FDA-approved iron oxide nanoparticle, ferumoxytol, for contrast-enhanced magnetic resonance imaging of the RPCS in mouse models of normal pregnancy and PAS. We then demonstrate the translational potential of this technique in human patients presenting with severe PAS (FIGO Grade 3C), moderate PAS (FIGO Grade 1), and no PAS.

METHODS

A T1-weighted gradient recalled echo (GRE) sequence was used to determine the optimal dose of ferumoxytol in pregnant mice. Pregnant Gab3 ^-/- mice, which demonstrate placental invasion, were then imaged at day 16 of gestation alongside wild-type (WT) pregnant mice which do not demonstrate invasion. Signal-to-noise ratio (SNR) was computed for placenta and RPCS for all fetoplacental units (FPUs) with ferumoxytol-enhanced magnetic resonance imaging (Fe-MRI) and used for the determination of contrast-to-noise ratio (CNR). Fe-MRI was also performed in 3 pregnant subjects using standard T1 and T2 weighted sequences and a 3D magnetic resonance angiography (MRA) sequence. RPCS volume and relative signal were calculated in all three subjects.

RESULTS

Ferumoxytol administered at 5 mg/kg produced strong T1 shortening in blood and led to strong placental enhancement in Fe-MRI images. Gab3 ^-/- mice demonstrated loss of hypointense region characteristic of the RPCS relative to WT mice in T1w Fe-MRI. CNR between RPCS and placenta was lower in FPUs of Gab3 ^-/- mice compared to WT mice, indicating higher degrees of vascularization and interruptions throughout the space. In human patients, Fe-MRI at a dose of 5 mg/kg enabled high uteroplacental vasculature signal and quantification of the volume and signal profile in severe and moderate invasion of the placenta relative to a non-PAS case.

DISCUSSION

Ferumoxytol, an FDA-approved iron oxide nanoparticle formulation, enabled visualization of abnormal vascularization and loss of uteroplacental interface in a murine model of PAS. The potential of this non-invasive visualization technique was then further demonstrated in human subjects. Diagnosis of placental invasion using Fe-MRI may provide a sensitive method for clinical detection of PAS.

Association of Implementing a Multidisciplinary Team Approach in the Management of Morbidly Adherent Placenta With Maternal Morbidity and Mortality

OBJECTIVE

To compare maternal outcomes in patients with morbidly adherent placenta managed in a multidisciplinary team setting compared with standard care.

DATA SOURCES

A literature search was performed for publications reporting multidisciplinary pathways in the management of cesarean delivery for patients with morbidly adherent placenta. EMBASE, MEDLINE, PubMed, PubMed Central, ClinicalTrials.gov, and Cochrane databases were searched.

METHODS OF STUDY SELECTION

Databases were searched for studies reporting maternal morbidity of patients with morbidly adherent placenta managed by a multidisciplinary team in a specialist center compared with standard care. Two independent reviewers applied inclusion and exclusion criteria to select included articles, with differences agreed by consensus. A total of 252 citations were reviewed; six studies comprising 461 patients were selected for the analysis.

TABULATION, INTEGRATION, AND RESULTS

Literature search was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results were reported as mean differences or pooled odds ratios (ORs) with 95% CIs. Estimated blood loss was significantly reduced in the multidisciplinary team group (mean difference -1.1 L, 95% CI -1.9 to -0.4, P=.004) and these patients had lower transfusion requirements (mean difference -2.7 units, 95% CI -4.1 to -1.2, P=.040). Those treated in a standard care setting were more likely to develop complications (OR 2.5, 95% CI 1.5-4.0, P<.001); however, there was no difference in length of stay between the two groups.

CONCLUSION

This meta-analysis highlights the improved maternal outcomes in patients with morbidly adherent placenta when managed by a multidisciplinary team in a specialist center. High-risk complex cases warrant expert management in centralized units.

Management of postpartum pulmonary embolism combined with retained placenta accreta: A case report

RATIONALE

Retained placenta accreta is an increasing obstetric problem in recent years, and pulmonary embolism (PE) during pregnancy and the postpartum period is a vital condition, but lack of standard therapy guidelines. This report describes a case of postpartum PE combined with retained placenta accreta.

PATIENT CONCERNS

A 27-year-old woman presenting with fever and dyspnea after delivery was admitted to our hospital with retained placenta accreta.

DIAGNOSES

The patient was diagnosed with the infection, postpartum PE, and residual placenta.

INTERVENTIONS

The antibiotics and low molecular weight heparin were initially started to cure the infection and control PE. Mifepristone was then used to promote the necrosis of residual placenta while long-term use of warfarin was served as continuous anticoagulant therapy. Hysteroscopic resection of retained placenta was not performed until thrombi had been almost disappeared after more than 2 months of anticoagulation therapy.

OUTCOMES

The patient's menstruation returned to normal within several weeks after hysteroscopic resection and she completely recovered from PE after 3 months of anticoagulant therapy.

LESSONS

Treatment of retained placenta accreta can be postponed when encountering complicated cases, such as postpartum PE. PE in perinatal stage can be managed referring to nonmaternal PE.

Evidence-Based Strategies for Maternal Stabilization and Rescue in Obstetric Hemorrhage

Obstetric hemorrhage is one of the most frequent causes of maternal death in the United States. More than 70% of maternal deaths from hemorrhage are preventable. State and professional quality care organizations have reduced severe maternal morbidity by more than 20% by implementing evidence-based guidelines. Successful hemorrhage management requires collaborative, multidisciplinary teams of trained health care personnel. Hemorrhage management's primary goal is to stop the bleeding before the occurrence of maternal hypovolemia, acidosis, coagulopathy, and death. Uterine atony is the primary cause of obstetric hemorrhage and can be managed with uterotonic agents, placement of noninvasive uterine tamponade balloons, and surgical procedures if needed. Women experiencing massive hemorrhage should be treated according to resuscitation care guidelines with avoidance of hypothermia, acidosis, and coagulopathy. Use of a massive transfusion protocol is warranted for best outcomes. Resources for institutional adoption of current collaborative standards for managing obstetric hemorrhage are identified in this article.

The significance and evolution of menstruation

Historically, the evolutionary origins of menstruation have been based on two theories: the ability to eliminate infectious agents carried to the uterus with spermatozoa and the comparative conservation of energy with menstruation compared to its absence. In the menstruating species, more recent theories have identified spontaneous decidualization as the key adaptive mechanism. Spontaneous decidualization is seen as a mechanism to provide the mother with protection from the invasive characteristics of the embryo. Physiologically, menstruation involves complex interactions of inflammation and vascular mechanisms to stabilize the endometrium and allow a regulated loss of endometrial tissues and blood. A variety of human illnesses can be better understood as vulnerabilities associated with these evolutionary developments, including recurrent pregnancy loss, placenta accreta, ectopic pregnancy, endometriosis, adenomyosis, dysmenorrhea, and chronic pelvic pain. While the evolutionary aspects of these diseases indicate why such illnesses can occur, in some instances, they also provide a basis for treatment, prevention and future research direction.